As cellular networks develop, cell sites will need time to reach targeted coverage levels. In the meantime, higher-power User Equipment (HPUEs) may be used for range extension in rural deployments and to enhance coverage in suburban/urban areas. Disadvantageously, there are Uplink (UL) interference concerns if HPUEs are deployed in areas where an access node density was designed for lower-power User Equipment (LPUEs) coverage; HPUEs will reach a Maximum Output Power (MOP) before it is necessary from a range extension perspective. While this improves throughput for the HPUE, UL interference noise rises and degrades UL performance overall from a system perspective.
For example, the 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) specifies User Equipment (UE) Power Classes in 3GPP TS 36.101 Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); UE radio transmission and reception (i.e., Release 8, December 2008; Release 9, December 2009; Release 10, March 2011; Release 11, September 2012; Release 12, September 2014; and Release 13, December 2015), the contents of which are incorporated by reference herein. While off-the-shelf UEs (e.g., Power Class 3 UEs) often transmit (Tx) at a Maximum Output Power (MOP) of +23 dBm, in Release 11 of the LTE standard, 3GPP proposed HPUEs able to Tx at a higher MOP of +31 dBm for low-band Frequency Division Duplex (FDD) spectrum, for example, to boost coverage in rural deployments and/or enhance throughput in suburban/urban areas. But, networks often neglect UE Power Class differences between HPUEs and other LPUEs, triggering handoff of HPUEs based on parameters set for LPUEs. Consequently, HPUE capabilities are not fully exploited and coverage/extension gains are unnecessarily limited. In addition, overall UL performance, for example, from a system perspective, may be degraded.
Overview
Systems and methods are described for extending coverage of a wireless device are disclosed. In one instance, mobility handoff parameters for a plurality of wireless devices may be set based on a lower power class device operating in a coverage area of an access node. A power report may be received at the access node from at least one wireless device of the plurality of wireless devices. A pathloss change may be calculated for the at least one wireless device based on the received power report. Based on the power report, calculated pathloss change, and set mobility handoff parameters, a handoff trigger point for the at least one wireless device may be adjusted.
In another instance, at least one wireless device operating in a coverage area of an access node may be instructed to report a power class at the access node. A power class delta for the at least one wireless device may be calculated at the access node. The power class delta may be calculated based on a difference of the reported power class of the at least one wireless device and a power class of a lower power class wireless device operating in the coverage area. The calculated power class delta may be applied to a set mobility handoff parameter. A handoff trigger point for the at least one wireless device may be adjusted based on the set mobility handoff parameter.
In another instance, a handover trigger threshold for a plurality of wireless devices located in a coverage area of an access node may be established. The handover trigger threshold may be established based on a common power class of the plurality of wireless devices. An attachment request may be received at the access node from at least one wireless device having a power class different from the common power class. Based on the reported power class, the handover trigger threshold for the at least one wireless device may be adjusted. The at least one wireless device may be instructed to extend its coverage until the adjusted handover trigger threshold is met.